U.S. patent number 6,835,162 [Application Number 10/119,031] was granted by the patent office on 2004-12-28 for automatic transmission system for vehicle.
This patent grant is currently assigned to Nissan Motor Co., Ltd.. Invention is credited to Kenichiro Murakami, Satoshi Sakakibara, Yasuhiro Yamauchi.
United States Patent |
6,835,162 |
Yamauchi , et al. |
December 28, 2004 |
Automatic transmission system for vehicle
Abstract
An automatic transmission system for a vehicle includes a
shift-by-wire system which converts a selected command operation
range of a range selector into an electric signal and which changes
an actual operation range of an automatic transmission into the
selected command operation range by driving an actuator according
to the electric signal. A lock mechanism restricts the operation of
the range selector when the shift-by-wire system is electrically
turned off regardless of the present operation range of the range
selector.
Inventors: |
Yamauchi; Yasuhiro (Kanagawa,
JP), Murakami; Kenichiro (Kanagawa, JP),
Sakakibara; Satoshi (Kanagawa, JP) |
Assignee: |
Nissan Motor Co., Ltd.
(Yokohama, JP)
|
Family
ID: |
18962816 |
Appl.
No.: |
10/119,031 |
Filed: |
April 10, 2002 |
Foreign Application Priority Data
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Apr 10, 2001 [JP] |
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2001-111168 |
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Current U.S.
Class: |
477/101;
74/473.12 |
Current CPC
Class: |
F16H
59/105 (20130101); F16H 59/12 (20130101); F16H
61/22 (20130101); Y10T 477/669 (20150115); F16H
2061/223 (20130101); Y10T 74/2003 (20150115); F16H
2059/746 (20130101) |
Current International
Class: |
F16H
59/08 (20060101); F16H 59/12 (20060101); F16H
59/10 (20060101); F16H 61/22 (20060101); F16H
59/00 (20060101); F16H 59/74 (20060101); F16H
059/74 () |
Field of
Search: |
;477/99,101
;74/473.12-473.15 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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197 52 752 |
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Jun 1999 |
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DE |
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199 13 005 |
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Oct 2000 |
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DE |
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0 324 469 |
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Jul 1989 |
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EP |
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478453 |
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Apr 1992 |
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EP |
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2-256951 |
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Oct 1990 |
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JP |
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5-322031 |
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Dec 1993 |
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JP |
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06001157 |
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Jan 1994 |
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JP |
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Primary Examiner: Lewis; Tisha
Attorney, Agent or Firm: Foley & Lardner LLP
Claims
What is claimed is:
1. An automatic transmission system for a vehicle, comprising: an
automatic transmission selectively taking a plurality of operation
ranges; a range selector operated by a driver of the vehicle to
select one of command operation ranges; a shift-by-wire system
converting a selected command operation range into an electric
signal and changing an actual operation range of the automatic
transmission into the selected command operation range by driving
an actuator according to the electric signal; a lock mechanism
restricting an operation of the range selector when the
shift-by-wire system is electrically turned off ; and a lock
canceling mechanism which is operable for canceling the restricting
operation of the lock mechanism, the shift-by-wire system being
electrically turned on in response to the canceling operation of
the lock canceling mechanism.
2. The automatic transmission system as claimed in claim 1, wherein
the shift-by-wire system is connected through a cancel switch to a
power supply source, the power supply source being connected to the
shift-by-wire mechanism through an ignition switch, the cancel
switch being turned on in response to the canceling operation of
the lock canceling mechanism.
3. The automatic transmission as claimed in claim 1, wherein the
shift-by-wire system is electrically turned off when an ignition
switch is turned off.
4. The automatic transmission as claimed in claim 1, wherein the
shift-by-wire system is electrically turned off when an abnormality
of the automatic transmission is detected.
5. An automatic transmission system for a vehicle, comprising: an
automatic transmission selectively taking a plurality of operation
ranges; a range selector selecting one of command operation ranges
in response to a driver's command; a lock actuator locking the
range selector in response to a command lock signal; a lock
canceling mechanism canceling a restricting operation of the lock
actuator according to a manual operation of a driver of the
vehicle; a shift actuator changing an actual operation range of the
automatic transmission in response to a control signal; a lock
canceling switch electrically turning on the shift actuator when
the lock canceling mechanism executes an canceling operation of the
restricting operation; and a control unit outputting the control
signal to the shift actuator according to the selected command
operation range of the range selector; wherein the lock actuator
locks the range selector when the shift actuator is electrically
turned off.
6. The automatic transmission system as claimed in claim 5, wherein
the control unit outputs the lock command signal to the lock
actuator at least when an ignition switch of the vehicle is turned
off and when the automatic transmission is put in an abnormal
state.
7. A method of controlling an automatic transmission system for a
vehicle, the automatic transmission comprising an automatic
transmission which selectively takes a plurality of operation
ranges, a range selector which is operated by a driver of the
vehicle to select one of command operation ranges and a
shift-by-wire system which converts the selected command operation
range into an electric signal and changes an actual operation range
of the automatic transmission into the selected command operation
range by driving an actuator according to the electric signal, the
method comprising: restricting the operation of the range selector
when the shift-by-wire mechanism is electrically turned off ; and
electrically turning on the shift-by-wire system in response to a
canceling operation of a lock canceling mechanism which is operable
for canceling the restricting operation of the lock mechanism.
8. An automatic transmission system for a vehicle, comprising:
transmission means for selectively taking a plurality of operation
ranges; selector means, operated by a driver of the vehicle, for
selecting one of command operation ranges according to a driver's
command; shift-by-wire means for converting a selected command
operation range into an electric signal and for changing an actual
operation range of the transmission means into the selected command
operation range according to the electric signal; lock means for
restricting the operation of the selector means when the
shift-by-wire means is electrically turned off ; and a lock
canceling mechanism which is operable for canceling the restricting
operation of the lock mechanism, the shift-by-wire system being
electrically turned on in response to the canceling operation of
the lock canceling mechanism.
Description
BACKGROUND OF THE INVENTION
The present invention relates to an automatic transmission system
for a vehicle.
A shift lever of an automatic transmission system for a vehicle is
provided with a shift lock mechanism for preventing a displacement
of shift lever until an ignition switch is again turned on when
parking range (P range position) is selected by a driver through
the shift lever under a condition that the ignition switch is
turned off.
Japanese Patent Provisional Publication No. (Heisei) 5-322031
discloses a shift-by-wire type automatic transmission system
wherein an operation of a shift lever is converted into an electric
signal. A manual valve and a parking mechanism of an automatic
transmission are controlled by an electrically operated actuator
according to the electric signal to change of an operation range of
an automatic transmission.
SUMMARY OF THE INVENTION
However, such a shift-by-wire type automatic transmission system is
further required to improve utility in combination with a common
shift lock mechanism.
It is therefore an object of the present invention to prove a
shift-by-wire type automatic transmission system which preferably
controls the operation of a range selector such as a shift lever so
as to prevent a discord between an operation range selected by the
range selector and an actual operation range selected in an
automatic transmission.
An aspect of the present invention resides in an automatic
transmission system which is for a vehicle and comprises an
automatic transmission, a range selector, a shift-by-wire system
and a lock mechanism. The automatic transmission selectively takes
a plurality of operation ranges. The range selector is operated by
a driver of the vehicle to select one of command operation ranges.
The shift-by-wire system converts the selected command operation
range into an electric signal and changes an actual operation range
of the automatic transmission into the selected command operation
range by driving an actuator according to the electric signal. The
lock mechanism restricts the operation of the range selector when
the shift-by-wire mechanism is electrically turned off.
Another aspect of the present invention resides in a method of
controlling an automatic transmission system for a vehicle, the
automatic transmission comprising an automatic transmission which
selectively takes a plurality of operation ranges, a range selector
which is operated by a driver of the vehicle to select one of
command operation ranges and a shift-by-wire system which converts
the selected command operation range into an electric signal and
changes an actual operation range of the automatic transmission
into the selected command operation range by driving an actuator
according to the electric signal, the method comprising restricting
the operation of the range selector when the shift-by-wire
mechanism is electrically turned off.
The other objects and features of this invention will become
understood from the following description with reference to the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a wiring block diagram of an automatic transmission
system according to a first embodiment of the present
invention.
FIG. 2 is a schematic view showing a range selecting mechanism in
an automatic transmission employed in the automatic transmission
system.
FIG. 3 is a circuit diagram showing an ignition switch and a shift
lock canceling switch employed in the automatic transmission system
of FIG. 1.
FIG. 4 is a side view showing a range selecting device in the
automatic transmission system of FIG. 1.
FIG. 5 is a plan view showing a shift lock mechanism of the range
selecting device.
FIG. 6 is a side view showing the shift lock mechanism.
FIG. 7 is a plan view employed for explaining the shift lock
mechanism.
FIG. 8 is a side view employed for explaining the shift lock
mechanism.
FIG. 9 is a plan view employed for explaining the shift lock
mechanism.
FIG. 10 is a side view showing a shift lock canceling mechanism of
the range selecting device.
FIG. 11 is a side view employed for explaining the shift lock
mechanism.
FIG. 12 is a side view showing a range selecting device employed in
a second embodiment according to the present invention.
FIG. 13 is a plan view of a shift lock mechanism of the second
embodiment.
FIG. 14 is a plan view employed for explaining the operation of the
shift lock mechanism.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 to 11, there is shown a first embodiment of an
automatic transmission system according to the present
invention.
As shown in FIG. 1, the automatic transmission system comprises a
control unit 1, a range selecting device 2 and an automatic
transmission 3 which are electronically connected with each other
through signal circuits to exchange information in the form of
electric signals through signal circuits. Further, control unit 1,
range selecting device 2 and automatic transmission 3 receive
electric power of battery 5 through electric power circuits.
Particularly, in reply to the turning-on of an ignition switch 7
(ING ON), a battery 5 supplies electric power to a main power
supply circuit (IGN power supply circuit) 6 through an ignition
relay (IGN relay) 8. Control unit 1 and a shift actuator 4 of a
shift-by-wire system for automatic transmission 3 receive electric
power from IGN power supply circuit 6. That is, the automatic
control transmission system employs a shift-by-wire shifting
system.
Range selecting device 2 comprises a shift button set 30 acting as
an operating section, a shift switch 12, a shift lock actuator 14
and a shift lock canceling switch 16. The operating section may be
a shift lever manipulated by a driver. Shift switch 12 detects a
range position selected by the driver through shift button set 30.
Shift lock actuator 14 controls a shift lock mechanism 13 which
prevents a change of the selected operation range during the
turn-off state of ignition switch 7 (IGN OFF state). Shift lock
canceling switch 16 is interlocked with a shift lock canceling
mechanism 15. Shift lock actuator 14 always receives electric power
from battery 5 since shift lock actuator 14 is directly connected
to battery 5 and is not affected by the turning on and off of
ignition switch 7.
Automatic transmission 3 comprises a shift actuator 4 and an
inhibitor switch 21, in addition to a torque converter, a gear
train and a hydraulic system. Shift actuator 4 comprises a relay
24, an amplifier 22 and a motor 23. Automatic transmission 3 makes
shifting upon being set in an actual operation range from a
plurality of operation ranges by the operation of shift actuator 4
according to the electric signals from control unit 1.
Control unit 1 comprises a shift control section 17, a fail
determining section 18 and a shift lock control section 20. Shift
control section 17 outputs an operation signal for a motor 23 to an
amplifier 22 of shift actuator 4 in automatic transmission 3 on the
basis of a state of shift switch 12 and a signal of inhibitor
switch 21 which is indicative of an actual range position of
automatic transmission 3. The operation of shift control section 17
is terminated when ignition switch 7 is turned off (IGN OFF). That
is, the shift actuator 4 of automatic transmission 3 and control
unit 1 constitute the shift-by-wire system (mechanism) so that the
shift-by-wire system converts the command operation range selected
in range selecting device 2 into an electric signal and changes an
actual operation range of the automatic transmission 3 into the
selected command operation range by driving shift actuator 4
according to the electric signal.
Fail determining section 18 determines an abnormality (FAIL) of the
automatic transmission system on the basis of signals from various
sections. When fail determining section 18 determines that the
automatic transmission system is in a fail state, the fail
determining section 18 outputs a fail signal to shift lock control
section 20 and a relay 24 of shift actuator 4 to shut off electric
power to shift actuator 4. Fail determining section 18 determines
that the automatic transmission system is in fail when a breakage
of a wire or over-current flowing is caused in one of the sections
in the automatic transmission system.
Shift lock control section 20 sends a drive signal to shift lock
actuator 14 to operate shift lock mechanism 13 when shift control
section 17 determines that the control is terminated in response to
IGN-OFF state or when fail determining section 18 determines that
the automatic transmission system is in the fail state. Further,
shift lock control section 20 sends a drive signal to shift lock
actuator 14 so as to cancel the operation of shift lock mechanism
13 when shift control section 17 determines that the automatic
transmission system is in IGN-ON state.
An engine starter relay 26 and an accessory relay 25 for a car
audio system and the like are further connected to battery 5
through ignition switch 5.
As shown in FIG. 2, a mechanical construction of a range selecting
mechanism in automatic transmission 3 employs motor 23 and a wire
cable (or rod) 27 through which the range selecting operation by
motor 23 is inputted into automatic transmission 3. The range
selecting operation of the range selecting mechanism of automatic
transmission 3 is achieved by the operations of a manual valve and
a parking mechanism of automatic transmission 3 in response to the
signal from control unit 1.
FIG. 3 shows a detailed circuit for ignition switch 7 and shift
lock canceling switch 16. Battery 5 is connected to ACC relay 25,
IGN relay 8 and starter relay 26 through an ignition switch 7, and
is connected to IGN relay through shift lock canceling switch 16.
As is clear from FIG. 3, according to the switch modes of OFF, ACC,
IGN and ST of ignition switch 7, the connation conditions of ACC
relay 25, IGN relay 8 and starter relay 26 relative to battery 5 is
changed.
On the other hand, by turning on shift lock canceling switch 16,
IGN relay 8 operates such that battery 5 supplies electric power to
IGN power supply circuit 6, as is similar to the operation in the
case of the turning on of ignition switch 7 (IGN ON), regardless
the turning on and off state of ignition switch 7. ACC relay 25 is
not affected by the operation of shift lock canceling switch
16.
FIGS. 4 to 6 show range selecting device 2, shift lock mechanism 13
and shift lock canceling mechanism 15.
Shift button set 30 is of a button type and acts as a manual
operation section of range selecting device 2. Shift button set 30
comprises shift buttons 30a, 30b, 30c, 30d, 30e and 30f
corresponding to selectable ranges such as P (parking) range, R
(reverse) range, N (neutral) range, D (drive) range, 2 range and 1
range, respectively. By pressing a desired one of shift buttons 30a
to 30f, shift switch 12 corresponding to the pressed button is
turned on so as to select a desired (command) operation range.
As shown in FIG. 5, a plurality of lock holes 32 are formed at
lower portions of the respective shift buttons 30a to 30f so that
each of keys 31a to 31f of a shift lock mechanism is insertable
into each lock hole 32. Each of keys 31a to 31f is installed on a
plate 33 through a spring 33 so as to be movable relative to plate
33. Both ends of plate 33 are installed on shift lock actuator 14.
Shift lock actuator 14 selectively takes one of two positions of a
forward position and a backward position, and is turned on
(energized) only when the vehicle is moving.
By forwardly driving shift lock actuator 14 to take the forward
position, plate 33 and keys 31a to 31f except for the pressed shift
button (shift button 30c of N range in FIG. 4) and key (30c)
corresponding to the pressed shift button are forwardly moved from
a state shown in FIGS. 5 and 6, and the other keys 31a, 31c, 31d,
31e and 31f are inserted into lock holes 32 of the corresponding
shift buttons 30a, 30b, 30d, 30e and 30f, respectively, as shown in
FIGS. 7 and 8. Since the pressed shift button (30c of N range) is
offset from lock hole 32 of the corresponding key 31c as shown in
FIGS. 7 and 9, it is not inserted into the lock hole 32.
Accordingly, displacements of the other shift buttons is restricted
(prevented) and therefore the shift lock is achieved.
By backwardly driving shift lock actuator 14 to take the backward
position, keys 31a to 31f are released from lock holes 32 and shift
button 30a 30f are released therefrom. Accordingly, the shift lock
state is canceled.
On the other hand, as a shift lock canceling mechanism 14 for
canceling the shift lock of shift lock mechanism 13, a shift lock
canceling cam 35 is provided at a center of plate 33 of shift lock
mechanism 13 as shown in FIGS. 5 and 10. Shift lock canceling cam
35 is formed into a right angled triangle and installed on plate 33
so that an oblique surface is faced with a shift lock canceling
button 36 operated by the driver, as shown in FIG. 10. Shift lock
canceling switch 16 interlocked with shift lock cancel button 36 is
disposed adjacent to shift lock cancel button 36.
By pressing shift lock canceling button 36 under the shift lock
state wherein keys 31a to 31f of shift lock mechanism 13 are
inserted into lock holes 32 of shift buttons 30a to 30f shown in
FIG. 10, an oblique surface at a lower surface of shift lock cancel
button 36 is contacted with shift lock cancel cam 35, and plate 33
is backwardly moved. Therefore, the shift lock is canceled thereby.
Further, shift lock canceling switch 16 is turned on in response to
the operation of shift lock canceling button 36.
By pressing shift lock cancel button 36 under a shift lock
condition that keys 31a to 31f are inserted into lock holes 32 of
shift buttons 30a to 30f, respectively as shown in FIG. 10, the
oblique surface of the shift lock canceling button 36 presses an
oblique surface of shift lock canceling cam 35 and moves plate 33
rearward to cancel the shift lock. Further, in response to the
operation of shift lock canceling button 36, shift lock canceling
switch 16 is turned on.
With this arrangement of the automatic transmission system
according to the first embodiment of the present invention, when
ignition switch 7 is put in IGN OFF state (IGN OFF), shift lock
control section 20 operates the shift lock mechanism so that shift
buttons 30a to 30f are put in the shift lock condition. Therefore,
when IGN OFF, that is, when the power supply of shift actuator 4 of
the shift-by-wire mechanism is turned off, even if the shift
position is set at a position except for P range, the displacement
of shift buttons 30a to 30f is restricted. This arrangement solves
a problem that when shift actuator 4 cannot be driven, the range
selected by shift buttons 30a to 30f becomes different from the
range of automatic transmission 3.
Further, when the automatic transmission system is put in a fail
state, shift lock control section 20 operates shift lock mechanism
13 so that shift buttons 30a to 30f are put in the shift lock
condition, and fail determining section 18 shuts off the power
supply to shift actuator 4. Therefore, during the fail state, this
arrangement according to the present invention prevents the
automatic transmission system from incorrectly performing, and
solves a problem that the range selected through shift buttons 30
to 30f becomes different from the range of automatic transmission
3.
On the other hand, when shift lock canceling mechanism 15 operates
to cancel the shift lock of shift lock mechanism 13, IGN relay 8
operates in reply to the turning on of shift lock canceling switch
16 regardless of the condition of ignition switch 7. By this
operation of IGN relay 8, electric power is supplied to IGN power
supply circuit 6. That is, shift actuator 4 is put in an operable
state according to the turning-on of shift lock canceling switch
16.
Therefore, even if shift buttons 30a to 30f are controlled after
the cancellation of the shift lock, the range selected by shift
buttons 30a to 30f corresponds with the range of automatic
transmission 3 by the above-discussed displacement restricting
(preventing) setting. That is, the above-discussed arrangement
according to the present invention prevents the discord between the
range selected by shift buttons 30a to 30f and the range of
automatic transmission 3.
Since the electronic circuit of the automatic transmission system
according to the present invention is arranged such that IGN relay
8 operates in reply to the turning on of shift lock canceling
switch 16, it is possible to supply electric power to control unit
1, shift actuator 4 and the like in a block by turning on IGN power
supply circuit 6 without independently controlling the power supply
to control unit 1, shift actuator 4 and the like.
Referring to FIGS. 12 to 14, there is shown a second embodiment of
the automatic transmission system according to the present
invention. The automatic transmission of the second embodiment
employs a lever-type operating section of range selecting device 2
and a shift-by-wire shifting system.
As shown in FIG. 12, a lever 50 of range selecting device 2 is
movable on positions corresponding to P range, R range, N range, D
range, 2 range and 1 range which are aligned in the fore-and-aft
direction. A shift switch 51 for detecting the position of lever 50
is provided on the base portion of lever 50.
A shift lock plate 53 of shift lock mechanism 52 is provided at a
side portion of lever 50. Shift lock plate 53 comprises a plurality
of engaged portions 54 and is formed into a tandem type. Lever 50
is capable of engaging with engaged portions 54. Both ends of shift
lock plate 53 is installed on a shift lock actuator 55. Shift lock
actuator 55 selectively takes one of two positions of a forward
portion and a backward position. Only when shift lock actuator 55
is moving, electric power is supplied to shift lock actuator
55.
By forwardly driving shift lock actuator 55 to take the forward
position, shift lock plate 53 is moved forward from a condition
shown in FIG. 13, and one of engaged portion 54 is engaged with
lever 50 as shown in FIG. 14. By this operation, the displacement
of lever 50 is restricted (inhibited) and therefore the shift lock
is achieved.
By backwardly driving shift lock actuator 55 to take the backward
position, shift lock plate 53 is moved backwardly, and engaged
portions 54 is released from lever 50. That is, lever 50 becomes
free from engaged portions 54 and therefore the shift lock is
canceled.
Although a shift lock canceling mechanism is not shown in FIGS. 13
and 14, a mechanism similar to shift lock cancel mechanism 15 shown
in FIG. 10 may be installed in the system. The other construction
of the second embodiment is basically the same as that of the first
embodiment shown in FIGS. 1 and 2. Accordingly, as is similar to
the button type operating section of range selecting device 2 of
the first embodiment, the automatic transmission system of the
second embodiment prevents the discord between the selected range
selected by range selecting device 2 and the actual range in
automatic transmission 3.
Each of shift lock mechanisms 13 and 52 may be arranged so as to
restrict the displacement of control section (shift button set 30
and lever 50) of range selecting device 2 at least from the parking
range.
This application is based on Japanese Patent Applications No.
2001-111168 filed on Apr. 10, 2001 in Japan. The entire contents of
these Japanese Patent Applications are incorporated herein by
reference.
Although the invention has been described above by reference to
certain embodiments of the invention, the invention is not limited
to the embodiments described above. Modifications and variations of
the embodiments described above will occur to those skilled in the
art, in light of the above teaching. The scope of the invention is
defined with reference to the following claims.
* * * * *